There is a "Chunked Encoding Transfer Heap Overflow" vulnerability in IIS. You telnet into port 80 of a possible target and enter the following commands:
A)POST /iisstart.asp HTTP/1.1
B)Accept: */*
C)Host: acme.com
D)Content

Question

Quizplus · Accepted Answer

The first line tells the server you want to use the POST method to communicate with the iisstart.asp file. You then pass it the rest of the data. Many remote exploits work simply by accessing the open port using telnet or netcat and knowing what to type.

There Is a "Chunked Encoding Transfer Heap Overflow" Vulnerability in IIS